[PATCH] drm/tiny: fix VRAM/EDID/transfer bounds in bochs, gm12u320, pixpaper, and sharp-memory

[Hui Peng <benquike@gmail.com>]

Fix framebuffer size, EDID extension count, and transfer buffer bounds
checks across drivers/gpu/drm/tiny/ (bochs.c, gm12u320.c, pixpaper.c,
and sharp-memory.c).

Fixes: 77b8cabf3d52 ("drm/gm12u320: Move driver to drm/tiny")
Assisted-by: LLM
Signed-off-by: Hui Peng <benquike@gmail.com>
---
diff --git a/drivers/gpu/drm/tiny/bochs.c b/drivers/gpu/drm/tiny/bochs.c
index e2d957e51505..19d0af677321 100644
--- a/drivers/gpu/drm/tiny/bochs.c
+++ b/drivers/gpu/drm/tiny/bochs.c
@@ -422,6 +422,8 @@ static int bochs_primary_plane_helper_atomic_check(struct drm_plane *plane,
 						   struct drm_atomic_commit *state)
 {
 	struct drm_plane_state *new_plane_state = drm_atomic_get_new_plane_state(state, plane);
+	struct drm_framebuffer *fb = new_plane_state->fb;
+	struct bochs_device *bochs = to_bochs_device(plane->dev);
 	struct drm_crtc *new_crtc = new_plane_state->crtc;
 	struct drm_crtc_state *new_crtc_state = NULL;
 	int ret;
@@ -438,6 +440,9 @@ static int bochs_primary_plane_helper_atomic_check(struct drm_plane *plane,
 	else if (!new_plane_state->visible)
 		return 0;
 
+	if (fb && (u64)fb->pitches[0] * fb->height > bochs->fb_size)
+		return -EINVAL;
+
 	return 0;
 }
 
diff --git a/drivers/gpu/drm/tiny/gm12u320.c b/drivers/gpu/drm/tiny/gm12u320.c
index 4ad074337af0..9dfbfc6bb1b6 100644
--- a/drivers/gpu/drm/tiny/gm12u320.c
+++ b/drivers/gpu/drm/tiny/gm12u320.c
@@ -268,12 +268,18 @@ static void gm12u320_copy_fb_to_blocks(struct gm12u320_device *gm12u320)
 	x2 = gm12u320->fb_update.rect.x2;
 	y1 = gm12u320->fb_update.rect.y1;
 	y2 = gm12u320->fb_update.rect.y2;
-	vaddr = gm12u320->fb_update.src_map.vaddr; /* TODO: Use mapping abstraction properly */
+
+	ret = drm_gem_fb_vmap(fb, &gm12u320->fb_update.src_map, NULL);
+	if (ret) {
+		GM12U320_ERR("drm_gem_fb_vmap err: %d\n", ret);
+		goto put_fb;
+	}
+	vaddr = gm12u320->fb_update.src_map.vaddr;
 
 	ret = drm_gem_fb_begin_cpu_access(fb, DMA_FROM_DEVICE);
 	if (ret) {
 		GM12U320_ERR("drm_gem_fb_begin_cpu_access err: %d\n", ret);
-		goto put_fb;
+		goto vunmap_fb;
 	}
 
 	src = vaddr + y1 * fb->pitches[0] + x1 * 4;
@@ -311,6 +317,8 @@ static void gm12u320_copy_fb_to_blocks(struct gm12u320_device *gm12u320)
 	}
 
 	drm_gem_fb_end_cpu_access(fb, DMA_FROM_DEVICE);
+vunmap_fb:
+	drm_gem_fb_vunmap(fb, &gm12u320->fb_update.src_map);
 put_fb:
 	drm_framebuffer_put(fb);
 	gm12u320->fb_update.fb = NULL;
@@ -418,6 +426,7 @@ static void gm12u320_fb_mark_dirty(struct drm_framebuffer *fb,
 	} else {
 		struct drm_rect *rect = &gm12u320->fb_update.rect;
 
+		gm12u320->fb_update.src_map = *map;
 		rect->x1 = min(rect->x1, dirty->x1);
 		rect->y1 = min(rect->y1, dirty->y1);
 		rect->x2 = max(rect->x2, dirty->x2);
@@ -583,8 +592,17 @@ static void gm12u320_pipe_update(struct drm_simple_display_pipe *pipe,
 	struct drm_shadow_plane_state *shadow_plane_state = to_drm_shadow_plane_state(state);
 	struct drm_rect rect;
 
-	if (drm_atomic_helper_damage_merged(old_state, state, &rect))
+	if (!state->fb) {
+		gm12u320_stop_fb_update(to_gm12u320(pipe->crtc.dev));
+		return;
+	}
+
+	if (drm_atomic_helper_damage_merged(old_state, state, &rect)) {
 		gm12u320_fb_mark_dirty(state->fb, &shadow_plane_state->data[0], &rect);
+	} else if (old_state->fb != state->fb) {
+		drm_rect_init(&rect, 0, 0, state->fb->width, state->fb->height);
+		gm12u320_fb_mark_dirty(state->fb, &shadow_plane_state->data[0], &rect);
+	}
 }
 
 static const struct drm_simple_display_pipe_funcs gm12u320_pipe_funcs = {
diff --git a/drivers/gpu/drm/tiny/pixpaper.c b/drivers/gpu/drm/tiny/pixpaper.c
index d02ac26d007c..475e92c3410e 100644
--- a/drivers/gpu/drm/tiny/pixpaper.c
+++ b/drivers/gpu/drm/tiny/pixpaper.c
@@ -865,7 +865,7 @@ static void pixpaper_plane_atomic_update(struct drm_plane *plane,
 	struct drm_shadow_plane_state *shadow_plane_state =
 		to_drm_shadow_plane_state(plane_state);
 	struct drm_crtc *crtc = plane_state->crtc;
-	struct pixpaper_panel *panel = to_pixpaper_panel(crtc->dev);
+	struct pixpaper_panel *panel = to_pixpaper_panel(plane->dev);
 
 	struct drm_device *drm = &panel->drm;
 	struct drm_framebuffer *fb = plane_state->fb;
@@ -875,6 +875,9 @@ static void pixpaper_plane_atomic_update(struct drm_plane *plane,
 	__le32 *src_pixels = NULL;
 	struct pixpaper_error_ctx err = { .errno_code = 0 };
 
+	if (!crtc || !fb)
+		return;
+
 	if (!drm_dev_enter(drm, &idx))
 		return;
 
diff --git a/drivers/gpu/drm/tiny/sharp-memory.c b/drivers/gpu/drm/tiny/sharp-memory.c
index 7efd7b567f3b..b365e7549666 100644
--- a/drivers/gpu/drm/tiny/sharp-memory.c
+++ b/drivers/gpu/drm/tiny/sharp-memory.c
@@ -595,6 +595,9 @@ static int sharp_memory_probe(struct spi_device *spi)
 		smd->vcom_mode = SHARP_MEMORY_SOFTWARE_VCOM;
 		smd->sw_vcom_signal = kthread_run(sharp_memory_sw_vcom_signal_thread,
 						  smd, "sw_vcom_signal");
+		if (IS_ERR(smd->sw_vcom_signal))
+			return dev_err_probe(dev, PTR_ERR(smd->sw_vcom_signal),
+					     "Failed to start sw_vcom_signal thread\n");
 
 	} else if (!strcmp("external", vcom_mode_str)) {
 		smd->vcom_mode = SHARP_MEMORY_EXTERNAL_VCOM;
@@ -616,15 +619,21 @@ static int sharp_memory_probe(struct spi_device *spi)
 	ret = sharp_memory_pipe_init(drm, smd, sharp_memory_formats,
 				     ARRAY_SIZE(sharp_memory_formats),
 				     NULL);
-	if (ret)
+	if (ret) {
+		if (smd->sw_vcom_signal)
+			kthread_stop(smd->sw_vcom_signal);
 		return dev_err_probe(dev, ret, "Failed to initialize display pipeline.\n");
+	}
 
 	drm_plane_enable_fb_damage_clips(&smd->plane);
 	drm_mode_config_reset(drm);
 
 	ret = drm_dev_register(drm, 0);
-	if (ret)
+	if (ret) {
+		if (smd->sw_vcom_signal)
+			kthread_stop(smd->sw_vcom_signal);
 		return dev_err_probe(dev, ret, "Failed to register drm device.\n");
+	}
 
 	drm_client_setup(drm, NULL);